A standard database command (or manipulation) language is TL1, which has been standardized by BellCore for public switching platforms (systems) and network equipment. This language is based on the CCITT Z.300 series recommendations for man-machine language.
Classical implementation methods would involve creating a lexical analyzer using the lex software available on virtually all UNIX platforms. Then a Yacc parser supplemented by custom code is created to handle the semantic processing. Unfortunately, these methods essentially hardcode the field names and associated values such that any variation in the syntax or semantics of a particular database view of a field requires a new software build. In typical systems where several different databases and/or languages are used by the same software this leads to a proliferation of software builds and significant inflexibility.
Because of these problems, independent languages and multiple schema capability are typically not available on-switching machine or on-switching platform because of these problems.